1. Field of the Invention
This invention relates in general to specula and, in particular, to vaginal specula. More specifically, but without restriction to the particular embodiments hereinafter described in accordance with the best mode of practice, this invention relates to a vaginal speculum including a smoke evacuation channel for efficiently removing smoke from an area undergoing a smoke producing medical procedure.
2. Discussion of the Related Art
Various surgical techniques have recently developed with the advent of electrosurgical technologies. Among these surgical techniques are those involving gynecological procedures such as, for example, hysterectomies and surgical treatment of cervical cancers. During this type of gynecological procedure, a vaginal speculum is typically employed to dilate the vaginal cavity so that the uterus or cervix may be operated upon in an unobstructed manner. Electrosurgical tools are then employed to carry out the extent of surgery required.
Electrosurgical techniques involve vaporization of tissue which necessarily produces some amount of smoke. This smoke can obscure the surgeon's view of the area undergoing surgery. In the area of gynecological surgery, there has thus been previously proposed vaginal specula including smoke tubes for removing the smoke produced by electrosurgical procedures. Such devices include the surgical speculum disclosed in U.S. Pat. No. 4,884,559 which issued Dec. 5, 1989 to J. H. Collins. The Collins speculum includes a lower blade and an upper blade which is provided with a separately mounted smoke tube or an internally formed hollow, each of which extends over substantially the entire length of the upper blade.
Prior vaginal specula incorporating smoke evacuation systems have employed smoke tubes that are either welded or soldered to metal specula, solvent bonded to plastic specula blades, or in the case of the Collins device, require additional fasteners spaced along the upper blade. These tube systems have limited rates of evacuation due to relatively small tube diameters and require a fastening means which involves added assembly time or manufacturing expense. Collins proposes an alternate smoke evacuation system for a speculum which includes a hollow formed in the upper blade. While this system provides added volume capacity for increasing the rate of smoke evacuation, this type of doubled walled upper blade with the hollow formed therebetween requires complicated and expensive machining or injection molding processes.